In recent years, a high-speed operation of a semiconductor integrated circuit device is in demand Such a high-speed operation mainly requires a reduction in size of a semiconductor device such as a transistor, a reduction in resistance of a wiring, and a reduction in dielectric constant of an interlayer dielectric layer. However, the high-speed operation based on such approaches has limitations.
As such, in order to realize further high-speed operation, silicon germanium (SiGe) or germanium (Ge) that is a semiconductor material having a higher carrier mobility is getting a lot of attention, instead of silicon (Si) as a semiconductor material used previously.
Such a Ge or SiGe is under consideration as a material for filling, as a Ge film or a SiGe film, a recess such as a trench or hole, which is formed in an insulating film such as a SiO2 film, a SiN film or the like, by a chemical vapor deposition (CVD) method.
However, a germanium-based film such as the Ge film or the SiGe film is known to have a high selectivity to an underlying film. In a case where the germanium-based film is formed on the insulating film, a silicon material such as amorphous silicon has been considered to be used as a seed.
However, the conventional method allows the germanium-based film to grow over the entire area even if a recess such as a trench or hole needs to be selectively filled. As such, the germanium-based film may be formed even on an unintended area other than the recess.